Photovoltaic solar trackers typically consist of one or more interconnected sections of torque tube that are elevated above the ground and oriented along a North-South axis by supports. One or more rows of photovoltaic modules are then attached to the interconnected sections of torque tube. A motor and drive assembly is used to rotate the torque tube so that the modules face East at sun up and to rotate back, Westward throughout the course of each day, approximately tracking the sun as it moves across the sky.
Early trackers—circa mid 2000's—were functional but very expensive. This was due in part to the overly complicated mechanical drive mechanisms and the fact that they had not been optimized for cost or to minimize materials. Every component that was unnecessarily, large, and expensive, created a ripple effect that required the other components to be equally robust to handle the weight and forces created by that component, which added to the cost and adversely affected reliability. These shortcomings, combined with the relatively high price of photovoltaics at that time, made the incremental cost of adding tracking unattainable. As a result, their use was fairly uncommon, other than in the largest arrays (e.g., multiple Megawatts).
Now that the price of photovoltaic modules has fallen dramatically to well below $1 per watt, there is renewed interest in solar trackers, even for smaller arrays (e.g., <1 megawatt). However, to compete fully with fossil fuel-based energy, it is critical that the cost for other system components, such as tracking systems also comes down. Therefore, there is a need for solar trackers that perform well and are optimized for cost, low weight, ease of installation and material usage.